Body Iron Store and its Association with Risk of First Episode of Spontaneous Lower Extremity Deep Vein Thrombosis/Pulmonary Embolism: A Case-Control Study

Background and objectives The association between body iron stores and risk of deep vein thrombosis/ pulmonary embolism (DVT/ PE) has not been studied among Indian subjects. This study aimed to evaluate the same and also study the association between iron stores and recanalization of affected veins at week-12. Methods This Case-Control with follow-up study enrolled 85 consecutive adult (>= 18 years) cases presenting with first episode of spontaneous, proximal lower extremity DVT/ PE and 170 age (+/- 3 years) and sex matched adult controls without DVT/ PE. Those with haemoglobin(Hb) < 9 g/dl, malignancies, serum creatinine >= 2 mg/dL, heart failure and concurrent infections/ inflammatory disorders were excluded. All participants underwent iron profile, serum ferritin light-chain (FtL) and hepcidin testing. Results Anaemia [OR = 2.3 (95% CI = 1.3-4.0), p = 0.001] and elevated RDW (RDW-CV > 15%) [OR = 2.3 (95% CI = 1.2-4.3), p = 0.012] were significantly associated with increased risk of DVT/ PE. Iron deficiency (ID, defined as serum ferritin < 30 mu g/L, along with TSAT < 20%) was not associated with DVT/ PE risk [OR = 0.8 (95% CI = 0.4-1.7), p > 0.05]. Serum FtL in the highest quartile (> 75th centile) was associated with higher risk of DVT/ PE (OR = 5, 95% CI = 2.6-9.6) and levels < 25th centile with protection against DVT/ PE (OR = 0.1, 95% CI = 0.01-0.32), compared to levels between 25th and 75th centiles (referent range). Highest DVT/ PE risk was associated with FtL > 90th centile [OR approximate to 12 (95% CI = 3.9-37.2)]. No associations were noted between serum hepcidin and DVT/ PE risk and ID and DVT recanalization at week-12. Conclusion Higher iron stores, rather than ID, were associated with increased risk of DVT/ PE among those with Hb >= 9 g/dL. Anaemia and elevated RDW were also associated with risk of DVT/ PE. ID was not associated with poorer DVT recanalization at week-12.

Automated summary

The association between body iron stores and the risk of deep vein thrombosis/pulmonary embolism (DVT/PE) among Indian subjects was studied. Anemia and elevated red cell distribution width (RDW) were significantly associated with increased risk of DVT/PE, while iron deficiency was not. These findings suggest that higher iron stores may be a risk factor for DVT/PE.